PA-18-676, Research on the Health of Women of Understudied, Underrepresented and Underreported (U3) Populations - An ORWH FY18 Administrative Supplement (PI SH Swan) Abstract We are applying for an administrative supplement to enrich enrollment of Asian-Americans in The Infant and Development Study (TIDES) by recruiting a supplemental sample of Asian mother-child dyads. This will allow us to examine health disparities among US women underrepresented in this ongoing cohort study by examining health status at 6 years in relation to levels of phthalates, which we have previously shown to have sexually dimorphic effects. In the first funding cycle of TIDES, a prospective study of pregnant women and their children conducted in 4 clinical sites (Minneapolis, MN, Seattle, WA, San Francisco, CA, and Rochester, NY), we demonstrated sex differences in the impact of phthalates on reproductive tract development; in the second funding cycle (TIDES II), we showed sexual-dimorphism in the impacts of phthalates on play behavior and language development. However, the generalizability of our study results is uncertain. Despite efforts to be inclusive at enrollment, the TIDES population includes too few Asian (only 38 of 699 TIDES families) to examine associations in this under-represented minority. This administrative supplement (TIDES-Diversity) will allow us to examine our study exposures and outcomes in a supplemental cohort of (N=50) 6-year old Asian children living in the catchment area of the Minneapolis TIDES site. We propose to recruit from a range of Asian groups including, Hmong, Asian Indian, and (non-Taiwanese) Chinese. Among the Hmong, the largest proportion of Asians in this area, reproductive-aged women have been found to have significantly higher levels of some phthalate metabolites, including a 2.7-fold higher concentration of MiBP and 1.6-fold higher concentration of MBzP than NHANES averages. Higher phthalate levels are associated with adverse outcomes across the lifespan, including increased rates of diabetes and insulin resistance - two conditions that disproportionately affect Asians, and the Hmong specifically. TIDES children are currently undergoing the 6-year study visit, at which anthropometric measures and psychosocial outcomes are being obtained. TIDES-Diversity participants will be asked to complete TIDES questionnaires and their children will be invited to participate in all phases of the TIDES II 6-year study visit including providing a urine sample for measurement of phthalate metabolites. Together with the 38 Asian families currently enrolled in TIDES II, we would then have data on 88 Asian families (comparable to the number of African American families participating in TIDES; N=81). With data collection made possible by this supplement we will be able to examine the heterogeneity of TIDES II study exposures and outcomes and modification of study associations by race/ethnicity. If these results suggest such effect modification, we will seek funding for the addition of TIDES-Diversity cohorts to all 4 TIDES centers.